Page 71 - Haematologica Atlas of Hematologic Cytology

CHAPTER 8 - Myeloproliferative neoplasms
AB
Figure 1 ssen al al al thrombocythemia ( ( ( T) (A) Peripheral blood smear showing thrombocytosis with platelet ani- socytosis Red cell and and and neutrophil morphology is is is normal (B) In In the the bone marrow megakaryocytes increased in in in number are are are are usually usually very large with abundant mature cytoplasm and and and and hyperlobulated nuclei In In ET erythroid and and and and granulocy c c c c c c c c c c c lineages are are are are are usually usually normal no no no no dysplasia and and and no no no no blast increase increase are are are are are observed ery ery ery rarely re re re re re re re re re culin bers are are are are minimally increased increased Ma or or or diagnos c c c c c c c c c c c c c criteria for ET include: platelet count ≥450x109/L bone marrow biopsy showing megakaryocy megakaryocy c c c c c c c c c c c c prolifera prolifera on on on with with increased increased number of of enlarged mature megakaryocytes with with hyperlobula- ted nuclei absence absence of of of of of World Health Organiza on on on on on (WHO) criteria for other myeloprolifera ve ve neoplasms
JAK2 CALR or or or or or or or or or or MPL muta on on on on on Presence of of of of a a a a a a a a a a a a a a a a a a a a a clonal marker or or or or or or or or or or absence absence of of of of evidence of of of of reac ve ve thrombocytosis is is is a a a a a a a a a a a a a a a a a a a a a minor minor criterion criterion For diagnosis diagnosis diagnosis all ma ma ma or or or or or or or or or criteria criteria criteria or or or or or or or or or the the rst 3 ma ma ma or or or or or or or or or criteria criteria criteria plus the the minor minor criterion criterion should be met Required criteria criteria criteria for diagnosis diagnosis diagnosis of of of of of post-ET myelo brosis brosis are represented by documenta on on on on of of of of of a a a a a a a a a a a a a a a a a a a a a previous diagnosis diagnosis diagnosis of of of of of WHO-de ned ET ET and presence of of of of of of bone marrow brosis brosis plus at at at at least least 2 2 of of of of of of the following addi onal onal criteria: anemia leukoerythro- blastosis increasing splenomegaly elevated lactate dehydrogenase level development of of of at at at at at least least 2 2 2 cons tu onal onal symptoms (>10% weight loss in in in in 6 months night sweats unexplained fever >37 5 C) (Thiele et al al 2017) AB
Figure 14 ssen al thrombocythemia blast phase A 75-year-old pa ent with a a a a a a a a a previous diagnosis of ET trea- ted ted for some years only with with an platelet therapy presented with with persistent fever Slight hepatomegaly moderate anemia mild leukocytosis and high high platelet count were found (A) Bone marrow smear reveals high high cellularity with numerous megakaryocytes and and and and massive in in ltra on on on on by blasts blasts (B) At higher magni ca on on on on blasts blasts are medium-lar-
ge sized show a a a a a a a a round or or or oval nucleus with loose chroma n n n n n n n n n n and and one or or or more prominent nucleoli and and agranular cytoplasm Blast cells were nega ve to to peroxidase reac on and expressed the the CD61 an an gen which is speci c c c c c c of the the megakaryocy c c c lineage whereas lymphoid and myeloid an an gens were absent Thus diagnosis of megakaryoblas c c c blast phase was made ET is characterized by a a a a a a a a a a a a generally long-las ng ng rela vely benign course However a a a a a a a a a a a a er er er er many years a a a a a a a a a a minority of pa ents (approx 10%) develop bone marrow brosis associated with myeloid metaplasia (post- ET ET myelo myelo brosis) Less than 5% of of ET ET pa ents develop a a a a a blast phase more frequently of of the myelomonocy c c or or megakaryocy c c type 58